Mud gun



Nov. 1935.

E. E. B Roslus MUD GUN Filed Oct. v18,. 1953 2 Sheets-Sheet, 1

E i. E

INVENTOR E. E. BROSIUS Nov. .19, 1935.

Filed Oct. 18, 1933 2 SlieetS-Sheet 2 BN w .w .www

PatentedfNov. 19, 1935 UNITEDv STATES PATENT OFFICE 7 Claims.

The present inventionl relates to so-called mud guns of the character utilized for stopping tapping holes or iron notches of blast furnaces at the completion of each furnace tapping operaion.

Heretofore it has been common practice for a considerable period of time to operate mud guns by means of a piston actuated by steam. While such equipment has performed the function for which it is designed, it is, nevertheless, openvto several objections. In the nrst place, it is not practical with steam pressure operated equipment, to have a steam generating equipment for each mud gun. This has necessitated the use, general1y,of a centralized source of steam pressure connected with individual pieces of apparatus. Many pieces of equipment, not only mud guns, but other devices, are commonly connected to the central generating plant. With steamoperated installations not only has diiiculty been encountered at times in the convenient location of the desired connections, butconsiderable difficulty has arisen from the tendency of steam to condense in the pipes and connections.

' This is particularly true where there are long steam lines" and where the demand on the steam lines is relatively slight, as it is in the case of a single mud gun. More objectionable than this, however, 1s the diiiiculty-either of assuring at all times a suicient pressure condition to perform the plugging operation, or to prevent a dropping of the steam pressure before the operation has been completed. For example, in plugging tapping holes after a furnace tapping operation, it is obvious that lt is desirable to provide equipment having such capacity that a plugging operation once started may be quickly completed.'

Not only this, but it is desirable that the plugging operation be accomplished under such conditions as to prevent the possibility of the furnace blowing outwardly through the mud gun barrel. When it is considered that it is of importance to be able to maintain full pressure within a blast furnace without fear of -any possibility of damage by reason of such blowing out, y

it will be appreciated that not only is an effective pressure connection essential, but it is likewise essential that an operator be assured at all times that the steam is ata full pressure.

It not infrequently happens that due to unusual demands on the steam generating unit, vthe pressure available for a given mud gun is reduced below that representing maximum emciency of operation. In some cases, either due to failure of the steam. generating equipment or due to a heavy overload on such equipment, an operator is unable to perform orl complete the 'tapping of a hole in a furnace.

With the present invention, the operator may be assured that at all times he can at least mainr tain such conditions as to hold the clay utilized for the plugging operation against the pressure within the furnace, even though it should be impossible, by reason of some mechanical failure, for him to complete the plugging operation.

In accordance with a preferred embodiment of my invention, there is provided in combination with the mud gun, a pressure supply means 'in the nature of a pump for circulating a liquid to the gun and.,eifective for producing the necessary pressure conditions.

Moreover, with the present invention, the liquid utilized for effecting the operation of the mud gun is conserved. In this respect, it differs from steam-operated apparatus in which an exhaustingoperation is necessitated during each complete cycle, it not being feasible to reclaim .the steam. Not only does such steam exhausting represent a waste, but it involves an element of danger, both from the standpoint of the temperature of the escaping steam and from interference with both vision and hearing occasioned while the steam is exhausting.

The invention may readily be understood by reference to the accompanying drawings, in 30 which Figure l is a longitudinal section through. a mud gun used in accordance with my invention;

Figure 2 is a top plan view of the mud gun assembly;

Figure 3 is an end elevation of the arrangement shown in Figure 2;

Figure 4 is a side elevational view of a typical installation showing the mud gun in an operative position; and i 40 Fig. 5 is a diagrammatic view illustrating a system of pressure connections for the gun.

Referring first to Figure 1 there is disclosed a plugging apparatus comprising a gun chamber or barrel 2 provided with a discharge nozzle or 45 outlet 3. Clay within the chamber is adapted to be discharged through the outlet 3 by the operation of a piston or plunger 4 secured to the forward end of an operating rod 5, this rod having a piston 6 at its opposite end operating with 50 a pressure cylinder 1. In Figure 1, the plunger l is shown at 4the forward limit of its ejecting stroke, whereas atthe beginning of a plugging operation it normally would be at the right hand side of the cylinder 'l as viewed in Figure l.

Intermediate the barrel 2 and the cylinder 1, there is provided a combined bearing and stuiiing box assemblyof such construction as not only to effectively guide the rod 5 during its reciprocal movements, but also to shield the interior of the cylinder 1 against any appreciable leakage.

Mounted above the gun chamber or barrel and its hydraulic cylinder 1 is a clay reservoir 9 of cylindrical form.` At the forward end of the reservoir-9, i. e., the left hand end as viewed in Figure I', there is a port or opening 10 through which material can be forced from the reservoir 9 into the forward end of the barrel 2 and out the discharge member 3. This opening I0 is preferably so 'located Aas to be adjacent the limit of travel of the plunger 4 in the gun chamber,

v whereby the plunger at the extreme forward limit of its travel acts to close the port I0 and cut off communication between the barrel 9 and the chamber 2. This is clearly shownin Figure 1 where the piston 4 is shown as blocking the passage I0.

Provided Within the clay reservoir ond plunger I-I which is carried on the forward end of a rod I2, this rod being similar to the rod 5. On the opposite end of the rod I2 there is a piston I3 within a second hydraulic cylinder I4, the cylinder I4l being'located above the cylinder 1.` There is a combined guiding and packing assembly I5 at the end of the cylinder I4 similarly arranged to the combined guiding and packing element 8.

In the embodiment of the invention illustrated in the drawings, the two sets of'cylinders are shown as having substantially parallel axes and being directly superimposed. This is particularly desirable in accordance with the present in-` 'be of relatively small diameter, whereby it is pos- ;sible to obtain a comparatively long stroke under extreme pressure conditions. In actual practice, I have found that desirable results are obtained by utilizing a fluid pressure of from 1400 to 1,600 lbs. to the square inch. In accordance with the usual`practice, the reservoir 9 may be provided with a hinged closure I6 which may be opened at the will of the operator to permit the reservoir 3 to be charged withv clay. Upon completion of the charging operation the closure I6 may be fastened in position in any desired manner.

For filling the gun chamber 2, a suitable cap (not shown) may be placed over the outlet 3 to prevent the escape of clay therefrom. The plunger II may then be `operated to force clay from the reservoir 9 into the gun chamber 2, lthe plunger 4 at 'this time being in@ its retracted position and the port I0 open. The gun chamber having been lled, a second charge of clay may then be put into the reservoir 9. When the two chambers 2 and 9 have been filled, the gun is ready for a plugging operation. When the plugging operation is to be effected, the gun is inclined at the position shown in Figure 3 in which position the discharge outlet 3 is adjacent the hole or nozzle to be plugged. The plugging may be accomplished either byfiirst exhausting the charge within the gun chamber 2 or by exhausting the charge within the reservoir 9. In view of the prevailing tendency of operators to first empty the reservoir 9,v this method of operation 9 is a sec-` will now be described. The piston 4 will be maintained in its retracted position at the extreme right hand end' of the cylinder as viewed in Figure l, and uid under pressure is supplied to the cylinder I4. At this time, the piston I3, ofcourse, 5

will be at the right hand end of the cylinder. The fluid will act to move the piston toward the left. This will cause the plunger II to force the clay from the reservoir' 9 through the port I0 out the discharge passage 3. After the reservoir 9 has been emptied, the plunger l'I will be kept in its projected position so as to prevent any substantial back-flow of clay through the port I0 and the plunger 4 will then be operated to expel the clay from the barrel 2 through the discharge 15 member 3. v.

In actual practice, the capacity of the gun chamber plus the capacity of the reservoir is suiileient to eiect a plugging operation of the usual tap opening. Should occasion require more 204 clay, however, than that provided by the combined capacities of both the gun chamber and the reservoir, the plunger II may be moved to the right, while the plunger 4 is maintained in its projected position and additional clay can be intro- 25 duced into the reservoir through the closure I6. Thereafter by slightly retracting the plunger 4 and advancing plunger II, the additional clay charged into the reservoir may be forced out into the tap hole where 'the plugging is taking- 30 place.`

rIhe use of the plunger 4 as a gate or valve for closing the opening Ill when the plunger is inits forward position enables a re-charging loperation of the character referred to, while maintaining 35 the necessary pressure on the clay previouslyA ejected into the opening to prevent the clay from blowing out through the barrelof the mud gun. This, of course, assures that a suilicient constant pressure be maintained in the cylinder 1 vat all 40 times to prevent any backing up of the clay dueto the back pressure in the furnace. In accordance with the present invention, the pressure for operating the pistons 6 and I3 is obtained by the use of a iluid pressure pump, such for instance, 4aA

as one which is commercially sold by American Fluid Motors Co. under the trade-mark Hele- Shaw and which is shown inJFigure '1 of my Patent 1,930,467, dated Oct. 1'7, 1933. Such pumps may be operated to maintain a substanlo tially constant fluid pressure with a variable output of the iiuid. By` reason of the provision of a pump of this character, a. volume of uid under pressure can be supplied to the cylinders 1 and I4 to operate the pistons 6 and I3 at the desired rate of speed and the pressure can be held constant.

As is customary in the art, one of the furnace columns designated I1, is provided with a suitable bracket I8, ,this bracket providing a pivotal l0 mounting for a 'gun boom I9, the boom being adapted to swing about the axis of a pivot pin 20 which pin is carried on the bracket I8, the axis of which is substantially parallel to the axis of the furnace column I1.v

Depending from the outer end of the boom is a gun bracket 2I rigidly secured to the-boom and provided at its lower end with an anti-friction roller 22. Secured to the gun is a trolley rail 23 under which the roller 22 passes and with which the roller engages, this roller and trolley rail cooperating to permit relative movement between the gun bracket 2l and the gun.V It also permits the gun to be dipped or tilted from a horizontal "A,

ure 3.

position to an inclined position as shown in Fig- Secured to thefurnace column I1 is a strap 24 having clips 26 which cooperate with an exhaust pipe 26. a pressure supply pipe 21 and a pressure supply pipe 28. As shown in the diagram in Figure 5, the yexhaust pipe 26 is common for both cylinders 1 and I4. The pipe .21 connects with the cylinder 1 and the line 28 nnects with the cylinderA I4. The clips 26 hold the respective pipes against movement relatively to the column, and each of the pipes 'is providedtwith one portion 29 of a exible joint, the axis of which coincides with the axis lof the pin 20. Cooperating with the portions 29A are other portions 36 carried, respectively, on pipe sections 26', 21' and 28'. These pipe sections are so shaped as to extend upwardly along the furnace column I1 into position adjacent one side of the boom I9, and they aresecured to the boom by a second strap 3 I Fastened to the end of the boom I9 is a plate 32 having openings through which the pipe sections 26', 21 and 28 extend. The outer end of each of these pipe sections is provided with one portion 33 of a flexible joint, the other portion 34 of which is carried by pipe sections 26", 21" and 28", respectively. These last mentioned pipe sections extend downwardly different distances and are provided on their lower end with portions 35 of flexible couplings, the other portions 36 of which are carried, respectively, by pipe sections 26"', 21"' and 28"'.

The pipe section 28' communicates with one crt in the casing of a four-port, two-way valve 31 which controls the hydraulic cylinder I4. The valve 31 is provided with side portions having a connection 38.to the rear end of the cylinder IIIy and a connection 39 to the front of said cylinder whereby with the valve 31 in one direction, fluid may be delivered to one end of the cylinder I4, while with the valve in the opposite direction.

fluid may be delivered tothe other end thereof.`

The pressure pipe section 21"' is connected to one port of a four-port, two-way valve 40 similar to the valve 31 and having an outlet port communicating through a connection 4I to the rear of the cylinder 1, and a second port communicating through a connection 42 to the front end of the cylinder 1.

The valve 3'! has an exhaust connection 43 communicating with an exhaust connection 4t provided for the valve 46, these two exhaust connections communicating with ythe exhaust pipe section 26".

The valves 3l and 40 are normally so set that fluid under pressure will be delivered to the rear ends of the cylinders 1 and I4 upon the delivery of fluid under pressure to the pressure lines 21 and 28. The pressure line 28 is provided with an oil lubricator 45 while the line 21 is provided with a similar oil lubricator 46, these two lubricators being effective for delivering a predetermined amount of oil to the pressure lines for speially lubricating the various flexible joints and the valves. Where the system is using as a fluid an oil which is also a lubricant, these special lubricators45 and 46 may be omitted. The pressure line 2.1 is provided with a globe or other manually operable valve 41 and the line 28 is similarly provided with a valve 48. These two lines both communicate with the outlet 49 of a suitable fluid pressure pump 50 of the output variable pressure type above referred to. Thispump is provided with an inlet connection 5I leading from a uid reservoir 62, The exhaust line 28 ydischarges fluid into this reservoir 52. There is thus provided for operating the cylinders a closed fluid circulating system in which the necessary opcr t ating pressure can be built up and maintained to effect the necessary operation of the mud gun. 5

The construction and relationship of the'various universal joints 29 and 30 are such that free swinging movement of the boom I9 is permitted for bringing the gun either into cooperative relation to the furnace or permitting movement thereof in the opposite direction. The flexible joints 33-34 and 36-36 are respectively so located that movement of the character described between the roller 22 and the trolley rail 2,3 is not interfered with, the axes of the various flexible joints coinciding in each instance substantially with the axes of movement of the various parts of the boom and gun assembly.

llhe control valves 48 and 49 may be located at a suitable distance from the gun itself and preferably adjacent an operators station. It has been found desirable with this thought in mind, to mount them on the gas house wall whereby an operator out of the zone of intensive heat may effectively control the supply of operating liquid i at will to either the hydraulic cylinder 1 or the cylinder I4.

`As before stated, the capacity of these cylinders is such that ordinarily the clay held therein will be more than sufficient for effectinga plugging operation. The plugging operation having been completed, the gun is swung to its inoperative position and the valves 31 and`4ll manually controlled as required to effect a re-charging of the gun cylinder o2 and the reservoir 9, as before described.

While I have not herein shown the splashei cylinder, the crane operating cylinder or the clamping cylinder, which ,are usually provided with equipment of this character, as is well known 40 to those skilled in the art, it will be understood that such cylinders may be provided in accordance with the usual practice.

With the construction herein shown, by closing one or the other of the control valves 48 and 49, 45 the pistons 6 and I3 may be absolutely locked in any position to which they may have been moved to thereby hold the clay in position and prevent blowing out of the furnace. Such an operation is not possible in a steam-orated unit, 50 for example, in which upon failure of the pressure supply, there is no means of holding the cylinders against movement, inasmuch as the steam previously admitted to the cylinders rapidly condenses to hold the same therein. Moreover, very gradual movement of the plungers may be effected, whereas with steam-operated units it is difficult to eilect small increments of movement, particularly in` retracting the plungers. The particular advantage of the invention can be seen in the case previously described where the charge of both the barrel 2 and the barrel 9 are insumcient to plug the tap hole in the furnace. I have previously pointed out that in this case the plunger I l is retracted while the plunger I0 is held in the projected position. Thus the plunger 4 prevents the clay from blowing back. It can be held in this position indefinitely because of the fact that there is no condensation or loss 'of the fluid in the closed circulating system. 70 -After the lplunger I I has been retracted, vaddtional clay can beput into the reservoir 9. With thel present invention it is thus possible to give a very slight retracting movement tothe plunger i 4 sufllcient to uncover the port III and then 'hold 75l thesplunger in this intermediate slightly retracted position while the additional clay is forced by operation of the plunger through the opening lll. With the steam operation ot a similar unit, diiilculty is encountered iirst in retracting the plunger 4 to a limited extent and then in holding the plunger l in the intermediate retracted pos ition. Either the steam pressure tends to propel the plunger 4 to the i'ull forward limit of its travel, or is insuilicient to prevent further back travel of the plunger-4 under the pressure of the clay. f Therefore, `the iluid circulating system of the present invention has peculiar adaptability to a two-cylinder unit of the type herein speciilcally l described.

While I have herein illustrated certain preferred embodiments of the invention, it will be understood that changes inthe construction and operation of the various parts may be made without departing either from the spirit of the present invention or the scope of the broader claims.

I claim:

1. A mud gun system comprising a gun having a plunger, an operating piston and .Cylinder for the plunger, a iiuid pressure reservoir, a pump, and a closed liquid circulating system with valves for alternately connecting either end of the cylinder with the pump or the reservoir.

2. A mud gun system comprising a gun hav- 'ink a plunger, an operating piston and cylinder for the plunger, a uid pressure reservoir, a variable output constant pressure maintaining pump unit, and a closed circulating system for alter# nately connecting either end of the cylinder with the pump c'r the reservoir, valve means in said system for selectively connecting either end oi the cylinder'with the pump orA reservoir, the system also having valve means for holding fluid under pressure in the cylinder.

3. A mud gun system comprising a gun having a plungenan operating piston andcylinder Jfor the plunger, a iluid pressure reservoir, ay pump, and a closed circulating system of valves for alternately connecting either end of the cylinder with the pump or the reservoir, the valves being effective also for holding a fluid pressure in either end of the cylinder to deiinitely lock thev cylinder against movement.

4. A 1 nud gun system comprising a gun having va barrel and a reservoir communicating there-,

with, the barrel and the reservoir being adjacent, a plunger in both the barrel and the reservoir, a piston connected with each plunger and a cylinder for each oi' said pistons, a liquid reservoir, a 15=Y pump connected with the liquid reservoir, and a circulating system including valves for connecting either end of each cylinder with the pump or with the liquid reservoir at will.

6. A mud gun system comprising a gun having a barrel and 'a reservoir communicating therewith, the barrel and the reservoir being adjacent, a plunger in both the barrel and the reservoir, a piston connected with each plunger and a cylinder for each of said pistons. a liquid reservoir, a

pump connected with the liquid reservoir, and a circulating system including valves -ior connect-'- ing either end o f each cylinder with the pump or' with the liquid reservoir at will, the valves of the system also being arranged to hold the liquid under pressure in the cylinders and thereby 'effectively lock the cylinders in a given position.

7. A mud gun system 'comprising a gun having a barrel and a reservoir communicating with the barrel, a plunger in the barrel and a plunger in 35 the reservoir, a separate piston for each of said two plungers and a cylinder for each of said pistons, a liquid pump, a liquid reservoir connected to the inlet side ofthe pump, a closed uid circulating system leading from the liquid reservoir 40 to each end of each cylinder and from the pump to each` end of each cylinder, valve means in the system for cutting off communication from the outlet oi' the pump lto either cylinder, and valve means in the system for alternately connecting each end of each cylinder withthe pump and with the liquid reservoir;

EDGAR E. BROSIUS.4 

